Africa will never have seen anything like it. Amid unfathomable grief, the death of Nelson Mandela will be marked with the biggest and most watched events ever organised on the continent.

South Africa’s president Jacob Zuma said last night: “Our beloved Madiba will be accorded a state funeral. I have ordered that all flags of the Republic of South Africa be lowered to half mast ... and to remain at half-mast until after the funeral.”

The funeral will rival that of Pope John Paul II in 2005, which drew five kings, six queens and 70 presidents and prime ministers as well as 2 million faithful. The closest British equivalent may have been the 1965 state funeral of Winston Churchill.

Every living American president is expected to attend, health permitting, along with foreign dignitaries ranging from Prince Charles to the Zimbabwean president, Robert Mugabe. Celebrities who considered themselves close to Mandela, such as Oprah Winfrey, are also set to fly in.

All this spells an unprecedented planning and security nightmare for South Africa at the very moment that it is plunged into mourning for its father figure. The country is likely to come to a virtual standstill for two weeks as Mandela’s death is marked in various ways; some of them spontaneous and impossible to predict.

“He is the hero of the planet,” a senior foreign diplomat said. “It’s going to be the biggest state funeral since Winston Churchill, and I think any country would struggle to organise that.”

An internal South African government document seen by the Guardian sets out a provisional 12-day schedule from the moment of death. Although it was drawn up more than a year ago and is subject to revision, it provides an insight into how officials have prepared for a historically unique moment.

“Body to be taken and moved to the mortuary under police guard, plans for possible live coverage are being worked on,” it says for day one.

On day three, foreign diplomats will be briefed in Pretoria and logistics for Mandela’s lying in state will be discussed. On day four, various dignitaries will visit the Mandela family.

By day six there will be a memorial service attended by dignitaries and organisational leaders “as the body will be there. The ceremony will be addressed by President Jacob Zuma, there will be screens outside the city hall, and possibly Soweto, Cape Town and various other places.”

According to the draft, oOn day eight, Mandela will lie in state at Pretoria city hall for three days. “Body will be kept there until very late on every day, and then removed to be prepared for the following day ... inside a coffin with glass at the top for viewing.”

On day nine, the South Africa military will rehearse for the official state funeral at the Union Buildings, where Mandela was inaugurated as president following the first democratic elections in 1994. International heads of state will arrive at airports in Pretoria and Johannesburg.

There will be more arrivals on day 10, along with street closures, “all security measures to be implemented, final preparations at the Union Buildings, including dropping of equipment to be used during the ceremony ... Body to be taken later for final dressing.”

A procession from the mortuary to the Union Buildings will take place on day 11, followed by a state funeral at the Union Buildings amphitheatre, attended by heads of state. It will be shown on screens in the grounds and Pretoria city hall, where massive crowds are expected.

But South African officials have purportedly told diplomats they should not expect their dignitaries to get VIP treatment - the priority is on South Africans, then other African leaders and fellow liberation movements, then the rest of the world.